From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sun, 6 Oct 2019 20:44:11 +0000 (+0300)
Subject: fixed the 32bit version
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=ld45_start_nothing;a=commitdiff_plain;h=78cf90d60c7cdbfcb8bc1d3e3d03a577d1b70f7b

fixed the 32bit version
---

diff --git a/Makefile b/Makefile
index 165c473..aadff36 100644
--- a/Makefile
+++ b/Makefile
@@ -37,13 +37,13 @@ data/sprsheet.inc: data/sprsheet.png
 
 .PHONY: clean
 clean:
-	rm -f $(bin) $(obj) bootldr.img floppy.img boot.img
+	rm -f $(bin) $(obj) bootldr.bin floppy.img boot.img
 
 .PHONY: disasm
-disasm: bootldr.disasm $(bin).disasm
+disasm: bootldr.disasm $(name).disasm
 
-bootldr.disasm: bootldr.img
-	ndisasm -b 16 -o 7c00h $< >$@
+bootldr.disasm: $(elf)
+	objdump -d $< -j .boot -j .boot2 -m i8086 >$@
 
 $(name).disasm: $(elf)
 	objdump -d $< -j .text -m i386 >$@
diff --git a/game.ld b/game.ld
index 52a25f5..6e2df60 100644
--- a/game.ld
+++ b/game.ld
@@ -21,6 +21,7 @@ SECTIONS {
 	. = 1M;
 	_main_start = .;
 
+	.startup : { * (*.startup); }
 	.text : { * (.text); }
 	.data : { * (.data); }
 
diff --git a/src/boot/boot.asm b/src/boot/boot.asm
index 693bba3..0b6fb04 100644
--- a/src/boot/boot.asm
+++ b/src/boot/boot.asm
@@ -87,6 +87,7 @@ get_drive_chs:
 	; read_sector expects a linear sector number in cx, converts it to CHS
 	; and loads the sector at es:bx
 read_sector:
+	push bx		; save dest offset
 	mov byte [read_retries], 3
 .read_try:
 	push cx		; save linear sector number
@@ -138,6 +139,7 @@ read_sector:
 	call putchar
 
 	pop cx
+	pop bx
 	ret
 
 abort_read:
diff --git a/src/boot/boot2.asm b/src/boot/boot2.asm
index d5884bc..0fac8fe 100644
--- a/src/boot/boot2.asm
+++ b/src/boot/boot2.asm
@@ -24,6 +24,7 @@ boot2_start:
 
 	mov al, 10
 	call ser_putchar
+	call clearscr
 
 	; enable A20 address line
 	call enable_a20
@@ -548,7 +549,7 @@ kbc_wait_write:
 	jnz kbc_wait_write
 	ret
 
-numbuf: resb 16
+numbuf: times 16 db 0
 
 
 	; this part is placed at the very end of all boot sections
diff --git a/src/data.asm b/src/data.asm
index 6da8bdd..e6eab2f 100644
--- a/src/data.asm
+++ b/src/data.asm
@@ -1,5 +1,7 @@
 ; vi:filetype=nasm ts=8 sts=8 sw=8
 
+	section .data
+
 	global sprsheet_cmap
 	global sprsheet_tiles
 %include "data/sprsheet.inc"
diff --git a/src/gfx.asm b/src/gfx.asm
index 796ede0..ca5cf74 100644
--- a/src/gfx.asm
+++ b/src/gfx.asm
@@ -46,8 +46,13 @@ init_gfx:
 	call set_palette_entry
 	inc cl
 	jnz .cmaploop
-	ret
 
+	; force color 0 to black
+	xor ax, ax
+	xor bx, bx
+	call set_palette_entry
+
+	ret
 
 	global clear
 clear:
diff --git a/src/main.asm b/src/main.asm
index 4b2a11a..243ff0d 100644
--- a/src/main.asm
+++ b/src/main.asm
@@ -1,23 +1,29 @@
 ; vi:filetype=nasm ts=8 sts=8 sw=8:
 	bits 32
-	section .text
-
 	extern init_gfx
 	extern clear
 	extern slow_sprite
 	extern wait_vsync
 	extern swap_buffers
 
+	; this is placed at the beginning of our binary at 1mb (see game.ld)
+	; and it's what gets executed directly by the boot loader
+	section .startup
+	jmp main
+
+	; start of main
+	section .text
+main:
 	call init_gfx
 
 main_loop:
 	call clear
 
-	push word 100
-	push word 160
-	push word 0
+	push dword 100
+	push dword 160
+	push dword 0
 	call slow_sprite
-	add esp, 6
+	add esp, 16
 
 	call wait_vsync
 	call swap_buffers